Ethernet is still the core of LAN (local area network) in view of technology. Conventionally, most data is transferred over Ethernet at a rate of 100 Mbps (million bits per second). Typically, an auto-negotiation mechanism is performed for rate or other conversions in order to increase the rate from 10 Mbps to 100 Mbps. However, the auto-negotiation mechanism is no longer appropriate in a Gigabit transferring rate, while one of the bottlenecks being the transferring medium. Typically, twisted pair lines and coaxial cables are employed as medium for LAN, with the signals transmitting along the twisted pair lines and coaxial cables in the form of electromagnetic waves. Thus, electromagnetic interference (EMI), cross talk or the like are occurring in the signal transmission. Typically, a metal shield is formed around the twisted pair line or coaxial cable for eliminating EMI and cross talk. However, such problems of EMI and cross talk are so serious in high frequencies that it would be too difficult to be solved with general approaches.
Thus, most undesirable factors are considered in designing a circuitry of a network IC in order to enable the network IC to operate normally in different operating environments including the worst cases, giving the designed network IC a higher tolerance. However, such designs increase circuit area and power consumption as a tradeoff. An internal regulator is usually provided in a Gigabit network IC for adjusting the default operating voltage of the IC, being controlled by a device (e.g., computer or the like). Rather than having the computer adjust the required operating voltage of the internal regulator in response to the quality of signals being transmitted along the medium in the meantime automatically, such adjustments could only be done by a network management staff member by operating a computer or the like in response to the current conditions and requirements.
Therefore, it is desirable among network IC designers to provide a novel method and device capable of decreasing power consumption, and at the same time achieving the required performance in order to overcome the inadequacies of the prior art.